Responding to news Clinton-allied billionaire Mark Cuban would be attending the debate at the invite of her campaign, Trump posted "If dopey Mark Cuban of failed Benefactor fame wants to sit in the front row, perhaps I will put Gennifer Flowers right alongside of him!" to Twitter.

If dopey Mark Cuban of failed Benefactor fame wants to sit in the front row, perhaps I will put Gennifer Flowers right alongside of him!

Flowers insisted she and Clinton had a 12-year affair, though the former president admitted to just one sexual encounter between the two, in 1977, two years after his marriage. Trump's team included a short (but soundless) clip from an infamous interview with the president on the topic in a recent campaign ad.

Odd move. Entire CW is Trump looks like a normal candidate, he wins. Now setting up a Gennifer Flowers fight instead. https://t.co/ImA2s2NVKG

On Twitter, some political commentators suggested the spat was evidence that Clinton and Cuban had successfully gotten under Trump's skin during one of the most crucial moments of his campaign, though others suggested perhaps the move had backfired.

Whether or not Flowers will actually attend, let alone sit in the front row, is currently unclear.